Technically, the delivery fee is usually $0-5, but that's not why it's so expensive.
As I said, there are hidden fees too, not just service and delivery fees. Each menu item will have a hidden increased cost. I noticed this once when I compared the line items to a bill I had in the restaurant versus my Doordash bill. They increased the price of every single item on the menu and the app doesn't tell you that they do this. Does this not happen in your country? I'd encourage you to do a test and check by looking at the prices of each item in the app versus going to the restaurant and seeing what their prices are.
Our delivery and service fees will also fluctuate depending on the date and time of day. It is not a constant number and will increase during dinner time and etc.